Apparatus for enameling articles



Feb. 10 1931. J. c. CROMWELL QPPARATUS FOR ENAMELING ARTICLES Filed June 13, 1928 INVENTOR Feb. 10, 1931. 'ROMWEL 1,792,284

APPARATUS FOR ENAMELING ARTICLES I Filed June 13, 1928 5 Sheets-Sheet 2 my 1m 1 11/1/1111 Feb. 10, 1931.

J. Cv CROMWELL.

APPARATUS FOR ENAMELING ARTICLES Filed June 13, 1928 5 Sheets-Sheet 5 INVENTOR /Z A z/wxa Patented Feb. 10, 1931 UNITED STATES PATENT OFFICE- J OHN G. CROMWELL, OF ALLIANCE, OHIO, ASSIGNOB TO THE STEEL'SANITARY COM- PANY, OI ALLIANCE, OHIO, A CORPORATIONOF OHIO APPARATUS FOR ENAMELING ARTICLES Application filed June 13,

The present invention relates broadly to the art of material treatment and handllng apparatus therefor, and more particularly to an improved apparatus specially adapted for Y an enlarged scale, on the line IIII of Figure 1; o

Figure 3 is a transverse sectional view, on an enlarged scale, on the line IIIIII of Figure 1; v

Figure 4 is an end elevational view of one form of article adapted to be handled in accordance with the present invention; and

Figure 5 is a longitudinal sectional view through the article of Figure 3 in supported position, certain of the parts being in ele vation. g

The present invention is centered around an improved furnace and conveyor for effecting the movement of articles to be enameled therethrough, and contemplates the provision of auxiliary equipment cooperating therewithfacilitating the preparatory operations and "the bringing of the articles in proper condition into position to be passed through the furnace.

In the drawings there is illustrated an enameling furnace comprising preheating and drying chambers 2 and 2', and an intermediate burning chamber 3.

As illustrated in Figure 2 of the drawings, the burning chamber comprises an enclosing wall 4, cooperating with partitions 5, dividing the burning chamber into individual burning chambers .6, 7 and 8. The preheating or drying chambers are located at the 1928. Serial No. 284,964.

common, with respect to the travel of articles, to all of the individual burning chambers 6,7 and 8.

Cooperating with all of the chambers and adapted to cooperate therewith to efiect the movement of a given article successively through the different chambers, is a conveyor 9, herein illustrated as of an overhead chain type, traveling on angles 10, constituting a track-way therefor. The conveyor is adapted to travel in the direction indicated by the arrows in Figure 1, whereby an article is carried first through one of the drying and preheating chambers into the burning chamber 6, and thence into the drying or preheating chamber 2'.

During the travel of an article through the chamber 6, it is. subjected to the highest temperature conditions prevailing in the installation for burning the ground coat onto the same. 'The continued travel of the conveyor carries the article with its burnt on ground coat into a spraying booth 11, in which the second coat of enamel, either white or colored, is applied to the article. Thereafter, the article so treated is carried through the chamber 2' into the burning chamber 7, wherein it is subjected to a temperature slightly lower than the temperature in the chamber 6, to effect the desired burning of the second coatin of the enamel. It will be apparent that during the travel of articles having the second coat thereon through the chamber 2', they are preheated by the articles previously heated in'the chamber 6. The articles leaving the chamber 7 in turn give up their heat to incoming articles passing to the chamber 6, and thereby efiect-preheating thereof.

The articles having the second coat burnt thereon then pass through a spraying booth 12, in which they have the third or final coat of enamel applied thereto. The articles thus coated are carried by the conveyor 9into and through the drying and preheating chamber 2, wherein they are preheated by the articles leaving the chamber 7 before they enter the burning chamber 8. In this chamber they are subjected to a temperature preferably lower than the temperature in the chamber 7. They then pass into the chamber 2' wherein they give up their heat to articles on the conveyor entering the burning chamber 7, and are in turn cooled by this loss of heat.

At this relatively lower temperature, they pass from the chamber 2' to a position adjacent a storing, shipping or handling zone 13, in which they are removed from the conveyor for subsequent disposition.

From the foregoing, it will be apparent that I provide a conveyor means common to three burning chambers, all operating at different temperatures, and common to two preheating or drying chambers into and through which the articles must pass both before and after each burning operation. in such manner as to effect a desirable heat interchange there-. between with a consequent conservation of the heat of previously burnt articles. Each drying or preheating chamber is in turn common to all of the burning chambers, the burning chambers being arranged in laterally off- ,set relationship, preferably side by side.

thereby providing approximately parallel paths of travel therethrough.

Each of the burning chambers is preferably provided with heating means in the form of one or more electric heating units 14, by means of which exactly the desired burning temperatures are maintained in the different zones. As before pointed out, the temperature conditions are preferably so controlled that the temperature in the chamber 6 is higher than the temperature in the chamber 7 the temperature in the ell amber 7 being in turn higher than the temperature in the chamber 8, so that during the burning of successive coatings, the articles are subjected to progressively lower temperature conditions, thereby precluding the possibility during subsequent burning operations of fusing the previously applied coatings.

In order to effect a further conservation in heat. I preferably surround all of the burning chambers with a chamber 15, adapted to beheated by a relatively inexpensive fuel, such as gas, oil, or coal, such fuels being effective for maintaining the outer walls of the burning chambers at any desired temperature equal to or'below the temperature in the burning chamber 8. Since the radiation of heat is directly proportional to tlie square of the temperature difference througn the walls, by maintaining a relatively high temperature outside of the walls of the burning chambers by the use of a relatively inexpensive fuel, the consumption of electric current is reduced to a-minimum. In actual practice only about five per cent. 5%) of the total heat is supplied by the units 14. although this percentage maybe varied as found desirable for the most satisfactory and economic operation of the installation.

The conveyors arepreferably of such construction that the loss of heat from the heating furnace is reduced to a minimum and at the same time the diiferent parts of the conveying mechanism are maintained at different temperatures, thereby permitting the maintenance of the desired lubrication for the carrying or supporting portions thereof. Such a condition may be obtained by the use of a mechanism of the general character disclosed in the patent to Beasley and MacDougall, No. 1,603,015, of October 12 1926. In accordance with such patent, special sealing means 16 is provided for the supporting hooks 17, mounted on .the conveyor and projecting into the furnace, and a separate hood 18 for the carrying rollers 19, both of the hoods cooperatingwith a suitable sealing material 20, of sand or the like.

The hood 18 is adapted to have a cooling medium such as air under pressure supplied thereto through a conduit 21 for keeping the tracks and rollers cool. In case of any pressure differential between the cooling medium and the furnace, the difference will be in favor of the cooling medium whereby in case of leakage, the leaka e will be from the hood into the furnace, rat er than from the furnace outwardly.

In Figures 4 and 5 I have shown by way of illustration only, one form of article adapted to be handled in accordance with the present invention. Such an article may comprise a bath tub of any desired construction herein illustrated as having end braces 22, formed with trunnion openings 23, adapted to receive the trunnions or hooks 24, on the supporting hooks 17. In this manner a tub is so supported that it may be turned about its longitudinal axis during the spraying operations to thereby facilitate the uniform application of the coatings thereto.

It will be apparent that the utility of the invention 'is not limited with respect to the character of the articles being treated, the invention being equally applicable to either larger or smaller articles.

Adjacent the chamber 2 there may be provideda dipping tank 25, with which cooperates a conveyor 26, in such manner as to permit the dipping of the articles preparatory to their passage into the furnace. If desired, the dipped articles may be subjected to a predrying operation in the drying chamber 27, through which the conveyor 26 also passes.

This conveyor is preferably so mounted as to pass at some point in a position adjacent the conveyor 9,- whereby' previously dipped and dried articles may be transferred from one conveyor to the other in order to permit treatment of the character referred to. Cooperating with the conveyor 26 is a pair of conveyors 28, adapted to travel in the direction indicated by the arrows for receiving articles from carrying means 29 and passing the'same through annealing chambers 30 and sand blasting rooms 31 to prepare them, where such preliminary operations are desirable, for application of the ground coat by dipping.

In order to provide for the continuous use of the furnace in cases where it is not desired, for any reason, to treat articles delivered or provided by the conveyor 26, I may provide a conveyor 32, cooperating with a dipping tank 33 anda drying chamber 34. The conveyor 32 at some point preferably travels-in a path adjacent a storage chamber 35, in which articles of any desired character may be stored preparatory to enameling. Such articles, for example, may be of the type adapted to be speciall treated in accordance with any of the wellown pickling processes.

The present invention in providing for the continuous passage of an article through three different burning zones without the necessity of any removal thereof from the conveyor enables the cost of the enameling operations to be materially reduced, and also increases materially the output of a given installation with a minimum amount of labor.

The elimination of hand labor heretofore required for the removal of articles from securing of articlesto the conveyor, particularly during the spraying operations, has resulted in minimizing the number of seconds.

It will be understood by those skilled in the art that changes in the construction and arrangement herein illustrated, as well as in the nature of the articles handled,,.may.be made without departing either from the spirit of the present invention or the scope of my broader claims.

' I claim v 1. A heat treating furnace, comprising three heat treating chambers in lateral offset relationship, and means common to all of said chambers and extending through, the roof portions thereof for carrying an article successively therethrough.

2. A heat treating furnace, comprising three heat treating chambers in laterally offset relationship, temperature maintaining means for each of said chambers, in means common to all of said chambers for carrying an article successively therethrough.

Y 3. An enameling furnace, comprising three burning chambers in side byside relationship, means common .to all of said chambers for carrying an article successively therethrough, and treating means cooperat ing with said common means.

4. An enameling furnace, comprising three burning chambers in side by 'siderelationship, means common to all of said chambers for carrying an article successively therethrough, and means in the chambers for 'maintainingprogressively lower temperatures in the successive chambers. 7

5. An enamelmg furnace comprismg a I plurality of burning chambers, electric units for maintaining'said burning chambers-at the desired temperatures, and a heating means for maintaining different tempera tures in the different chambers a drying chamber common to all of said burnlng chambers, and means common to said burning chambers and said .drying chamber for carrying an article therethrough.

7. A heating furnace comprising a plurality of high temperature chambers in laterally ofi'set relationship, means for maintaining different temperatures therein, and a plurality of drying chambers each common to all of said high temperature chambers.

8. A heating furnace comprising a plurality' of high temperature chambers in laterally ofi'set relationship, means for maintaining different temperatures therein, a plurality of drying chambers each common to all of said high temperature chambers, and means common to all chambers for conveying articles therethrough.

9. In an enameling apparatus, a furnace,"

10. In an enameling apparatus, a furnace comprising a plurality of burning chambers,

a conveyor common to all of;said'burning chambers, and a plurality of independent conveyors for delivering different articles to a position-adjacent said first named con-,

veyor.

comprising aplurality of burning chambers, a conveyor common to all of said burning 11. In an enameling apparatus, a furnace,

chambers, a'pluralityof independent con' veyors for delivering diflerent articles to a position adjacent said first named conveyor, and drying means cooperating witheach of said last mentioned conveyors. 12. A heating furnace comprising a plurality of high temperature chambers in laterally offset relationship, means for maintaining different temperatures therein, a plurality of drying chambers, each common to all of said high temperature chambers, and means for conveying articles through all of said chambers.

13. Agheating furnace comprising a plurality of high temperature chambers in laterally ofl'set relationship, means for'maintaining different temperatures in the respective chambers, a drying chamber common to all of"'sa id high temperature chambers, and means for conveying articles through all of said chambers.

In testimony whereof I have hereunto set my hand. JOHN C. CROBTWELL. 

